As a traditional naval grade, CPO was senior to a petty officer, and was the highest enlisted grade in organizations like Starfleet and the US Navy. In comparison to infantry ranking systems, this rank was approximately equivalent to the more senior sergeant grades.

In "Mirror, Mirror", Captain Kirk, saved by an enlisted man from Chekov, who intended to assassinate him, was told that "Mr. Chekov was going to make me a chief, sir."

In Star Trek IV: The Voyage Home, a chief petty officer contacts the CDO Commander Rogerson, regarding a power drain in the energy systems of the aircraft carrier Enterprise. The CPO's voice is not heard on screen, but the commander responds to the question "Yes, chief. We're tracking that too."

Information pertaining to the Star Trek films "senior chief petty officer" and "master chief petty officer" ranks originated from Robert Fletcher's personal costuming notes (p. 9, seen here) and later confirmed in multiple lots sold in the It's A Wrap! sale and auction. Props designated as "master chief petty officer, second class" were apparently designed and created, but did not appear on Fletcher's notes, were also among the costume props sold in It's A Wrap!. [1][2][3]

Additionally, the revised shooting script for Star Trek IV was prefaced with several production notes, including one that stated: "Please note that Master Chief Petty Officer Rand now first appears in Scene 25 and in all subsequent Starfleet Command scenes," replacing the previous script note reference to her being a lieutenant. A similar note appeared during the production of The Motion Picture, which originally listed her as an ensign, but was revised to chief (no sleeve stripes), due to her position as the transporter chief.